Refrigerator unit for container

ABSTRACT

A refrigerator unit is configured for a container in which it is possible to know the quantity of air that is ventilated. The refrigerator unit is equipped with a ventilation mechanism, an opening degree detecting mechanism, and a recording unit. The ventilation mechanism ventilates the air inside the container. The opening degree detecting mechanism acquires ventilation data related to the quantity of air ventilated by the ventilation mechanism. The recording unit records the ventilation data acquired by the opening degree detecting mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 10/530,181 filed on Apr. 4, 2005, pending, allowed. The entiredisclosure of U.S. patent application Ser. No. 10/530,181 is herebyincorporated herein by reference. U.S. patent application Ser. No.10/530,181 is the U.S. National Stage application of PCT/JP2004/006021,and claims priority to Japanese Patent Application No. 2003-123493,filed on Apr. 28, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to a refrigerator unit for a container.

2. Background Information

For some time, refrigerator units for container have been used to coolthe inside of containers used for freight transport and the like. Someof these refrigerator units for container are equipped with ventilationunits for ventilating the interior of the container. For example, in thecase of a container used for transporting fruits and vegetables, it isnecessary to provide an appropriate degree of ventilation of the airinside the container in order to keep the fruits and vegetables fresh. Aventilation unit is therefore used to accomplish the ventilation of theinterior of the container (see Japanese Laid-Open Patent Publication No.9-280720).

Meanwhile, there is a need to know the quantity of air that is exchangedby the ventilation units used in container refrigeration units. In theexample presented above, since the ventilation affects the freshness ofthe fruits and vegetables, knowing the quantity of air that has beenventilated is useful for maintaining the freshness of the fruits andvegetables. Also, if the quantity of ventilation is known, a transportcompany transporting fruits and vegetables can provide a fruit andvegetable owner with a guarantee that an appropriate degree ofventilation is being conducted.

However, it is difficult to know the quantity of air that is ventilatedto and from conventional container refrigeration units like that justdescribed.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a refrigerator unitfor container for which it is possible to know the quantity of air thatis ventilated.

A refrigerator unit for container in accordance with the first inventionis equipped with a ventilation unit, an acquisition unit, and arecording unit. The ventilation unit ventilates the air inside thecontainer. The acquisition unit acquires ventilation data related to thequantity of air ventilated by the ventilation unit. The recording unitrecords the ventilation data acquired by the acquisition unit. Theventilation data is not limited to data that indicates the quantity ofventilated air directly; it is also acceptable for the ventilation datato be data that indicates the quantity of ventilated air indirectly.

With this refrigerator unit for container, the interior of the containeris ventilated and ventilation data related to the quantity of ventilatedair is recorded. Consequently, it is possible to review the recordedventilation data. Thus, with this refrigerator unit for container, it ispossible to know the quantity of ventilated air.

A refrigerator unit for container in accordance with the secondinvention is a refrigerator unit for container according to the firstinvention, further equipped with a first output unit. The first outputunit is configured to output the quantity of air ventilated by theventilation unit based on the ventilation data recorded by the recordingunit.

With this refrigerator unit for container, the quantity of airventilated by the ventilation unit is outputted by the first outputunit. Thus, with this refrigerator unit for container, it is possible toeasily know the quantity of ventilated air.

A refrigerator unit for container in accordance with the third inventionis a refrigerator unit for container according to the first invention,further equipped with a second output unit. The second output unit isconfigured to output the ventilation data recorded by the recordingunit.

With this refrigerator unit for container, the ventilation data isoutputted by the second output unit. Consequently, if the ventilationdata is data that directly indicates the quantity of ventilated air, thequantity of ventilated air can be known directly. Meanwhile, if theventilation data is data that indirectly indicates the quantity ofventilated air, the quantity of ventilated air can be known indirectly.Thus, with this refrigerator unit for container, it is possible toeasily know the quantity of ventilated air.

A refrigerator unit for container in accordance with the fourthinvention is a refrigerator unit for container according to any one ofthe first to third inventions, wherein the ventilation unit has aventilation passage and an opening/closing member. The ventilationpassage serves as a passage through which the ventilated air passes. Theopening/closing member opens and closes the ventilation passage. Theventilation data includes opening degree data indicating the degree towhich the opening/closing member has opened the ventilation passage.

With this refrigerator unit for container, the interior of the containeris ventilated by opening and closing the ventilation passage with theopening/closing member. Consequently, the quantity of ventilated air isaffected by the degree to which the opening/closing member opens theventilation passage. Thus, with this refrigerator unit for container, itis possible to know the quantity of ventilated air based on the openingdegree data.

A refrigerator unit for container in accordance with the fifth inventionis a refrigerator unit for container according to the fourth invention,wherein the opening/closing member is configured to open and close theventilation passage by being moved in a manual fashion.

With this refrigerator unit for container, the opening/closing member isconfigured to open and close the ventilation passage by being moved in amanual fashion. Conventionally, it is difficult to know the quantity ofventilated air when the opening degree of the ventilation passage ischanged manually. For example, if the opening/closing member is manuallymoved more than once during a transport, at the end of the transport itis difficult to know the history of how the opening degree of theventilation passage has changed. However, with this refrigerator unitfor container, the opening degree data is recorded by the recordingunit. Thus, with this refrigerator unit for container, it is possible toknow the quantity of ventilated air.

A refrigerator unit for container in accordance with the sixth inventionis a refrigerator unit for container according to the fourth or fifthinventions, wherein the acquisition unit has an opening degree detectingmeans. The opening degree detecting means detects the opening degreebased on the amount of movement of the opening/closing member.

With this refrigerator unit for container, the opening degree detectingmeans detects the opening degree based on the amount of movement of theopening/closing member. As a result, the opening degree data can beacquired easily based on the movement amount of the opening/closingmember.

A refrigerator unit for container in accordance with the seventhinvention is a refrigerator unit for container according to the sixthinvention, wherein the acquisition unit has a transmitting meansconfigured to transmit the movement amount of the opening/closing memberto the opening degree detecting means.

With this refrigerator unit for container, the transmitting meanstransmits the movement amount of the opening/closing member to theopening degree detecting means. As a result, the movement amount of theopening/closing member can be transmitted to the opening degreedetecting means even if the opening/closing member and the openingdegree detecting means are in separated positions.

A refrigerator unit for container in accordance with the eighthinvention is a refrigerator unit for container according to the seventhinvention, further equipped with a thermally insulated wall. Thethermally insulated wall is made of a thermal insulation material and isarranged and configured to separate the interior and exterior of thecontainer. The transmitting means is a member imbedded in the thermallyinsulated wall.

Refrigerator units for container are generally provided with a thermallyinsulated wall in order to maintain the temperature of the containerinterior. If the transmitting means is installed on the outside of thethermally insulated wall in a position facing the exterior of thecontainer, it will affect the exterior appearance of the container.Conversely, if the transmitting means is installed on the inside of thethermally insulated wall in a position facing the interior of thecontainer, it is possible that the ability of the transmitting means totransmit will be disturbed when the temperature of the containerinterior is extremely low.

However, with this refrigerator unit for container, the transmittingmeans is embedded in the thermally insulated wall. As a result, thetransmitting means is prevented from affecting the external appearanceof the container. Also, the transmitting means can transmit in atrouble-free manner without being affected by the temperature of thecontainer interior.

A refrigerator unit for container in accordance with the ninth inventionis a refrigerator unit for container according to the seventh or eighthinventions, further provided with a temperature detecting means and acorrection unit. The temperature detecting means detects the ambienttemperature surrounding the transmitting means. The correction unitcorrects the opening/closing member movement amount transmitted by thetransmitting means based on the ambient temperature.

With this refrigerator unit for container, the opening/closing membermovement amount transmitted by the transmitting means is corrected basedon the ambient temperature. As a result, even if the transmitting meanselongates or shortens due to the temperature, the movement amount of theopening/closing means can be detected accurately.

A refrigerator unit for container in accordance with the tenth inventionis a refrigerator unit for container according to any one of the fourthto ninth inventions, wherein the recording unit is configured to recordventilation data when the opening degree of the opening/closing memberis changed.

With this refrigerator unit for container, ventilation data is recordedwhen the opening degree of the opening/closing member is changed. As aresult, it is possible to know with good precision how the quantity ofventilated air has changed due to changes in the opening degree of theopening/closing member.

A refrigerator unit for container in accordance with the eleventhinvention is a refrigerator unit for container according to any one ofthe first to tenth inventions, wherein the recording unit is configuredto record ventilation data when the refrigerator unit for containerstarts running.

With this refrigerator unit for container, ventilation data is recordedwhen the refrigerator unit for container starts running. As a result,ventilation data can be obtained from the time when the refrigeratorunit for container starts running.

A refrigerator unit for container in accordance with the twelfthinvention is a refrigerator unit for container according to any one ofthe first to eleventh inventions, wherein the recording unit isconfigured to record ventilation data each time a specific amount oftime elapses or at a specific time of day.

With this refrigerator unit for container, the ventilation data isrecorded each time a specific amount of time elapses or at a specifictime of day. As a result, it is possible to know how the quantity ofventilated air changes with respect to a specific repeated time intervalor a specific time of day.

A refrigerator unit for container in accordance with the thirteenthinvention is a refrigerator unit for container according to any one ofthe first to third inventions, wherein the ventilation unit has aventilation passage and an air speed detecting means. The ventilationpassage serves as a passage through which the ventilated air passes. Theair speed detecting means detects the speed of the air passing throughthe ventilation passage. The ventilation data includes the air speeddata detected by the air speed detecting means.

With this refrigerator unit for container, the air speed data detectedby the air speed detecting means is recorded. The speed of the airpassing through the ventilation passage indicates the quantity ofventilated air indirectly. Thus, with this refrigerator unit forcontainer, it is possible to know the quantity of ventilated air becausethe air speed data is recorded.

A refrigerator unit for container in accordance with the fourteenthinvention is a refrigerator unit for container according to any one ofthe first to third inventions, wherein the ventilation unit has aventilation passage and a blower device. The ventilation passage servesas a passage through which the ventilated air passes. The blower devicegenerates a flow of air that is ventilated through the ventilationpassage. The ventilation data includes output data from the blowerdevice.

With this refrigerator unit for container, the output data of the blowerdevice is recorded. The output of the blower device indicates thequantity of ventilated air indirectly. For example, the larger theoutput of the blower device, the larger the quantity of ventilated air;the smaller the output of the blower device, the smaller the quantity ofventilated air. Thus, with this refrigerator unit for container, it ispossible to know the quantity of ventilated air because the output datais recorded.

A refrigerator unit for container in accordance with the fifteenthinvention is a refrigerator unit for container according to any one ofthe first to third inventions, wherein the ventilation unit has aventilation passage and a pressure detecting means. The ventilationpassage serves as a passage through which the ventilated air passes. Thepressure detecting means detects the pressure difference between theinlet and outlet of the ventilation passage. The ventilation dataincludes the pressure difference data detected by the pressure detectingmeans.

With this refrigerator unit for container, the pressure difference datadetected by the pressure detecting means is recorded. The pressuredifference between the inlet and outlet of the ventilation passageindicates the quantity of ventilated air indirectly. For example, thelarger the pressure difference between the inlet and outlet of theventilation passage, the larger the quantity of ventilated air; thesmaller the pressure difference between the inlet and outlet of theventilation passage, the smaller the quantity of ventilated air. Thus,with this refrigerator unit for container, it is possible to know thequantity of ventilated air because the pressure difference data isrecorded.

A refrigerator unit for container in accordance with the sixteenthinvention is a refrigerator unit for container according to any one ofthe first to third inventions, wherein the ventilation data includesfreight quantity data related to the quantity of freight loaded in thecontainer.

With this refrigerator unit for container, freight quantity data relatedto the quantity of freight loaded in the container is recorded. Thequantity of freight loaded in the container affects the pressuredifference between the interior and exterior of the container. Thepressure difference between the interior and exterior of the containeraffects the quantity of air that is ventilated. Thus, with thisrefrigerator unit for container, it is possible to know the quantity ofventilated air because the freight quantity data is recorded.

A refrigerator unit for container in accordance with the seventeenthinvention is a refrigerator unit for container according to any one ofthe first to sixteenth inventions, wherein the ventilation data is datathat indirectly indicates the quantity of air ventilated by theventilation unit. Also, this refrigerator unit for container is furtherprovided with a conversion unit configured to convert the ventilationdata into a quantity of air.

With this refrigerator unit for container, the ventilation data isconverted into a quantity of air by the conversion unit. Thus, even ifthe ventilation data is data that indirectly indicates the quantity ofventilated air, the quantity of ventilated air can be known directly byconverting the ventilation data into the quantity of ventilated air.

A refrigerator unit for container in accordance with the eighteenthinvention is a refrigerator unit for container according to theseventeenth invention, wherein the conversion unit has a plurality ofdifferent converting means adapted to different ventilation unitconfigurations.

The relationship between the ventilation data and the quantity of airoften differs depending on the constituent features of the ventilationunit. Consequently, it is difficult to convert the ventilation dataaccurately when the same conversion formula is used irregardless of theconstituent features of the ventilation unit.

With this refrigerator unit for container, however, the ventilation datais converted into a quantity of air using a plurality of differentconverting means adapted to different ventilation unit configurations.Thus, with this refrigerator unit for container, the ventilation datacan be converted more accurately into the quantity of ventilated air.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the external appearance of therefrigerator unit for container 1.

FIG. 2 is a side cross sectional view showing of the refrigerator unitfor container 1.

FIG. 3( a) shows the ventilation mechanism 4 in a completely closedstate.

FIG. 3( b) shows the ventilation mechanism 4 in an opened state.

FIG. 3( c) shows the ventilation mechanism 4 in a completely openedstate.

FIG. 4 is a schematic view of the opening degree detecting mechanism 5.

FIG. 5 illustrates how the opening degree detecting mechanism 5 detectsthe opening degree.

FIG. 6 is a side cross sectional view in the vicinity of the thermallyinsulated wall 26.

FIG. 7 is a control block diagram.

FIG. 8 is a graph plotting the first conversion formula F1 and thesecond conversion formula F2.

FIG. 9 is a front view of the control panel 72.

FIG. 10 illustrates an example of the output indicating the ventilationquantity and other information.

FIG. 11 is a flowchart indicating the procedure for logging andoutputting the ventilation quantity.

FIG. 12( a) is a schematic view illustrating a case in which air speeddata is detected.

FIG. 12( b) is a schematic view illustrating a case in which output datais detected.

FIG. 12( c) is a schematic view illustrating a case in which pressuredifference data is detected.

FIG. 13( a) is a schematic view illustrating a case in which the openingdegree of the ventilation passage 40 is detected using a photoelectricsensor 66.

FIG. 13( b) is a schematic view illustrating a case in which the openingdegree of the ventilation passage 40 is detected using a reed switch 67.

FIG. 13( c) is a schematic view illustrating a case in which themovement of the opening/closing member 41 is transmitted by means of agear.

FIG. 14( a) shows an opening/closing member 41 configured to open andclose the ventilation passage 40 by rotating.

FIG. 14( b) is a schematic view illustrating a case in which themovement of the opening/closing member 41 is transmitted by means of awire 51.

FIG. 14( c) is a schematic view illustrating a case in which themovement of the opening/closing member 41 is transmitted by means of agear.

FIG. 15 is a schematic view illustrating a case in which the ventilationpassage 40 is provided in a position that is separated from the firstchamber R1 or the second chamber R2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Constituent Featuresof Refrigerator Unit for Container

A refrigerator unit for container 1 that employs an embodiment of thepresent invention is shown in FIGS. 1 and 2. FIG. 1 is a perspectiveview of the external appearance of the refrigerator unit for container 1and FIG. 2 is a side cross sectional view of the refrigerator unit forcontainer 1 when it is mounted to a container C. The refrigerator unitfor container 1 is a device for maintaining a prescribed temperature inthe interior IS of the freight container C and is mounted to an openingof the container C in such a manner as to separate the interior IS ofthe container C from the exterior OS of the same. The refrigerator unitfor container 1 is provided with a frame 2, refrigerant circuitcomponent parts 3, a ventilation mechanism 4 (ventilation unit), anopening degree sensing mechanism 5 (acquisition unit), various sensors 6(see FIG. 7), and a control unit 7.

Frame

The frame 2 has a generally sheet-like shape and is mounted in such afashion as to block one side of the container C. As shown in FIG. 2, theframe 2 is provided with an exterior storage space SP1 and an interiorstorage space SP2.

The exterior storage space SP1 has a recessed shape and is formed in alower portion of a front face 21 on the side of the frame 2 that facesthe exterior OS of the container C. The exterior storage space SP1 isisolated from the interior IS of the container C and communicates withthe exterior OS of the container C. The upper portion of the front face21 has a flat shape that is generally parallel to the verticaldirection.

The interior storage space SP2 is arranged between the front face 21 anda rear panel 22. The rear panel 22 faces the interior IS of thecontainer C and is separated from the front face 21 by a prescribeddistance. The interior storage space SP2 spans from the rear (rear panelside) of the external storage space SP1 to space above the exteriorstorage space SP1 and communicates with the interior IS of the containerC through air vents 23, 24 provided near the top and bottom ends of therear panel 22. A plate-shaped fan guide 25 is provided in a generallyhorizontal state in the interior storage space SP2. The an evaporatorfan 36 (described later) is mounted to the fan guide 25. The interiorstorage space SP2 is divided by the fan guide 25 and evaporator fan 36into a first chamber R1 located above the fan guide 25 and a secondchamber R2 located below the fan guide 25.

A thermally insulated wall 26 is provided on the rear side of an upperportion of the front face 21 between the interior storage space SP2 andthe exterior OS and on the rear side of a lower portion of the frontface 21 between the interior storage space SP2 and the exterior storagespace SP1. The thermally insulating wall 26 is made of a thermalinsulation material and is arranged and configured to separate theinterior IS and exterior OS of the container C. The thermally insulatedwall 26 serves to suppress the movement of heat between the interior ISand exterior OS of the container C.

Refrigerant Circuit Component Parts

The refrigerant circuit component parts 3 include such parts as acondenser 30, a compressor 31, an expansion valve 32 (see FIG. 7), andan evaporator 33 and these parts constitute a refrigerant circuit.

The condenser 30, the compressor 31, and the expansion valve 32 arehoused in the external storage space SP1. The external storage space SP1also houses a condenser fan 34 and a condenser fan motor 35. Thecondenser fan 34 is rotated by the condenser fan motor 35 and serves toproduce a flow of air that is drawn into the exterior storage space SP1from the exterior OS, passes through the condenser 30, and is dischargedto the exterior OS (see unshaded arrow A1).

The evaporator 33 is housed in the second chamber R2 of the interiorstorage space SP2 on the rear side of the upper portion of the frontface 21. The internal storage space SP2 also houses an evaporator fan 36and an evaporator fan motor 37. The evaporator fan 36 and evaporator fanmotor 37 are arranged above the evaporator 33. The evaporator fan 36 isprovided in the opening of the fan guide 25 and is positioned betweenthe first chamber R1 and the second chamber R2. The first chamber R1 ispositioned on the inlet side of the evaporator fan 36 and the secondchamber R2 is positioned on the outlet side of the evaporator fan 36.The evaporator fan 36 is rotated by the evaporator fan motor 37 andproduces an interior air flow. The interior air flow flows from theinterior IS of the container C through the air vent 23 at the upper endof the rear panel 22 and into the first chamber R1 of the interiorstorage space SP2 (see unshaded arrow A2). The interior air flow thenflows from the first chamber R1 through the opening of the fan guide 25and into the second chamber R2, where it passes through the evaporator33 arranged in the second chamber R2. Then, the interior air flow flowsthrough the vent 24 at the lower end of the rear panel 22 to theinterior IS (see unshaded arrow A3).

Ventilation Mechanism

The ventilation mechanism 4 serves to ventilate the interior IS of thecontainer C and is provided with a ventilation passage 40 and anopening/closing member 41.

The ventilation passage 40 is a passage through which the ventilated airpasses and has an intake passage 42 and an exhaust passage 43. Theintake passage 42 and exhaust passage 43 are provided so as to bealigned above and below each other in an upper portion of the frontsurface 21; the inlet passage 42 is positioned above the exhaust passage43. The exhaust passage 42 is the passage through which air is drawninto the first chamber R1 from the exterior OS of the container C and isarranged and configured to communicate from an intake port 44 to thefirst chamber R1 through the thermally insulated wall 26. The exhaustpassage 43 is the passage through which air is discharged to theexterior OS of the container C from the second chamber R2 and isarranged and configured to communicate to an exhaust port 45 and theexterior OS through the thermally insulated wall 26. The intake port 44and the exhaust port 45 are provided in an upper portion of the frontface 21 and arranged so as to face the exterior OS with a prescribedvertical spacing there-between. As shown in FIG. 3, the intake port 44and the exhaust port 45 have the shapes of trapezoids arranged such thatthe upper and lower bases are parallel to the vertical direction. Theupper edges of the intake port 44 and the exhaust port 45 are horizontaland the bottom edges are slanted.

The opening/closing member 41 serves to open and close the ventilationpassage 40. The opening/closing member 41 is provided such that itslides freely up and down over the front face 21. The opening/closingmember 41 serves to adjust the quantity of ventilated air by adjustingthe opening degree of the intake port 44 and the exhaust port 45 inaccordance with its slide position. As shown in FIG. 3( a), theopening/closing member 41 has the shape of a rectangle that is long inthe vertical direction in a frontal view and is provided with a squareopening 46 in the center thereof.

When the ventilation passage 40 is closed, the opening 46 of theopening/closing member 41 is positioned between the intake port 44 andthe exhaust port 45 such that the intake port 44 and the exhaust port 45are closed by the opening/closing member 41. As shown in FIG. 3( b), theopening cross sectional areas of the intake port 44 and exhaust port 45increase in accordance with the amount of movement of theopening/closing member 41 when the opening/closing member 41 is slid inthe vertical direction. When the opening/closing member is moved in thisway and the exhaust passage 40 is opened, pressure differences causesthe interior IS of the container C to be ventilated. The pressuredifferences mentioned here are the pressure difference between theinterior IS and the interior storage space SP2 and the pressuredifference between the exterior OS and the interior storage space SP2.Since the first chamber R1 is positioned on the inlet side of theevaporator fan 36, its pressure is lower than the pressures of both theinterior IS and the exterior OS. Consequently, air is drawn from theinterior IS to the first chamber R1 through the air vent 23. Likewise,air is drawn from the exterior OS to the first chamber R1 through theintake port 44 and intake passage 42. The air drawn into the firstchamber R1 is pulled through the opening of the fan guide 25 by theevaporator fan 36 and delivered to the second chamber R2. Since thesecond chamber R2 is positioned on the outlet side of the evaporator fan36, its pressure is higher than the pressures of both the interior ISand the exterior OS. Consequently, a portion of the air delivered to thesecond chamber R2 is discharged to the exterior OS through the exhaustpassage 43 and the exhaust port 45. Meanwhile, the remainder of the airdelivered to the second chamber R2 is sent to the interior IS throughthe evaporator 33 and the air vent 24. In this way, with thisrefrigerator unit for container 1, the pressure difference generated bythe evaporator fan 36 is utilized to ventilate the container C. Bymoving the opening/closing member 41, the opening degree of theventilation passage 40 is adjusted and thus the ventilation quantity isadjusted. As shown in FIG. 3( c), the ventilation passage 40 iscompletely open when the positions of the opening 46 of theopening/closing member 41 and the intake port 44 are aligned.

When the opening/closing member 41 is slid in the opposite direction asjust described, the opening cross sectional areas of the intake port 44and exhaust port 45 decrease in accordance with the amount of movementof the opening/closing member 41. The ventilation passage 40 is fullyclosed when the opening 46 of the opening/closing member 41 ispositioned between the intake port 44 and the exhaust port 45 (see FIG.3( a)). A graduated scale is provided in near the opening/closing member41 and the opening/closing member 41 is moved manually using this scaleas an indicator of the ventilation quantity.

Opening Degree Detecting Mechanism

The opening degree detecting mechanism 5 is configured to acquireopening degree data (ventilation data) indicating the opening degree ofthe ventilation passage 40. The opening degree data indicates thequantity of air ventilated by the ventilating mechanism 4 (hereinaftercalled “ventilation quantity”) indirectly. As shown in FIG. 4, theopening degree detecting mechanism 5 is provided with an opening degreedetecting device 50 (opening degree detecting means) and a wire 51(transmitting means) configured and arranged to transmit the amount ofmovement of the opening/closing member 41 to the opening degreedetecting device 50.

The opening degree detecting device 50 is arranged in the exteriorstorage space SP1 and serves to detect the opening degree of theventilation passage 40 based on the movement amount of theopening/closing member 41. The opening degree detecting device 50 has awire winding drum 52 and a position meter 53. The wire winding drum 52has a circular shape for winding the wire 51 and is configured to rotatein accordance with the movement of the wire 51 (see unshaded arrow A6).The position meter 53 serves to detect the rotational angle of the wirewinding drum 52 and send the detected rotational angle to a controller7. In short, the position meter 53 can detect the opening degree of theventilation passage 40 by detecting the movement amount and position ofthe opening/closing member 41 based on the rotational angle of the wirewinding drum 52.

The wire 51 is a metal wire member configured and arranged to transmitthe movement amount of the opening/closing member 41 to the openingdegree detecting device 50. The wire 51 is arranged to span from theupper portion of the front face 21 where the opening/closing member 41is provided to the exterior storage space SP1 where the opening degreedetecting device 50 is arranged and, as shown in FIG. 5, the wire 51links the opening/closing member 41 and the wire winding drum 52together. FIG. 5 illustrates the linkage of the opening/closing member41 and the wire winding drum 52 in a simplified schematic manner. Asshown in FIG. 6, the wire 51 is inserted through a lead-through pipe 54embedded in the thermally insulated wall 26. The lead-through pipe 54passes from the upper portion of the front face 21 where theopening/closing member 41 is provided, through the interior of thethermally insulated wall 26, and down into the exterior storage spaceSP1 and serves to guide the wire 51 from the upper portion of the frontface 21 to the external storage space SP1. The wire 51 moves through thelead-through pipe 54 (see unshaded arrow A5) in accordance with themovement of the opening/closing member 41 (see unshaded arrow A4) andthereby transmits the movement of the opening/closing member 41 to theopening degree detecting device 50.

Thus, with this opening degree detecting mechanism 5, theopening/closing member 41 and the opening degree detecting device 50 canbe arranged in separated positions because the movement amount of theopening/closing member 41 is transmitted to the opening degree detectingdevice 50 by the wire 51.

Sensors

The sensors 6 include an exterior temperature sensor 61 (temperaturedetecting means) for detecting the temperature of the exterior OS of thecontainer C and an interior temperature sensor 62 for detecting thetemperature of the interior IS of the container C (see FIG. 7). Theexterior temperature, interior temperature, and other informationdetected by the sensors are sent to the controller 7.

Controller

The controller 7 is a device for controlling the refrigerator unit forcontainer 1 and is arranged in the external storage space SP1. As shownin FIG. 7, the controller 7 has a control unit 70 comprising a CPU orthe like, a memory 71, a control panel 72 for displaying information andmaking entries to control, an output unit 78, etc.

The control unit 70 is connected to the compressor 31, the condenser fanmotor 35, the expansion valve 32, the evaporator fan motor 37, and thesensors 6 and serves to control the operation of the refrigerator unitfor container 1. The control unit 70 is also connected to the positionmeter 53 of the opening degree detecting device 50 and is configured tolog (record) the ventilation quantity in the memory 71 based on theinformation detected by the opening degree detecting device 50. Thecontrol unit 70 has a conversion unit 73, a correction unit 74, and arecording unit 75.

The conversion unit 73 converts the opening degree data, which indicatesthe ventilation quantity indirectly, into the ventilation quantity. Morespecifically, the conversion unit 73 is configured to convert themovement amount of the opening/closing member 41 detected by the openingdegree detecting device 50 into a quantity of ventilated air. Since theopening cross sectional areas of the intake port 44 and exhaust port 45are adjusted when the opening/closing member 41 moves, the movementamount of the opening/closing member 41 corresponds to the quantity ofventilated air. Thus, the quantity of ventilated air can be calculatedusing a conversion formula that indicates the correspondence between themovement amount of the opening/closing member 41 and the quantity ofventilated air. The conversion unit 73 is provided with a firstconversion formula F1 (conversion means) and a second conversion formulaF2 as shown in FIG. 8 and is configured to use either conversionformula, whichever is selected. The first conversion formula F1indicates the correspondence between the movement amount of theopening/closing member 41 and the quantity of ventilated air in a casewhere a protective screen is not mounted to the intake port 44 andexhaust port 45. The second conversion formula F2 indicates thecorrespondence between the movement amount of the opening/closing member41 and the quantity of ventilated air in a case where a protectivescreen is mounted to the intake port 44 and exhaust port 45 and isdifferent from the first conversion formula F1. The protective screenserves to prevent contaminants from entering the interior IS of thecontainer C from the exterior OS and is mounted to the intake port 44and exhaust port 45. Since the pressure difference between the firstchamber R1 and the exterior OS is different in a case where a protectivescreen is mounted to the intake port 44 and exhaust port 45 than in acase where a protective screen is not provided, the first conversionformula F1 and the second conversion formula F2 are different. Thus, amore accurate conversion can be accomplished by using the conversionformulas F1, F2 selectively depending on the constituent features of theventilation mechanism 4.

The correction unit 74 corrects the movement amount of theopening/closing member 41 transmitted by the wire 51 based on theexterior temperature. More specifically, since the wire 51 expands andcontracts as the temperature changes, error occurs in the movementamount of the opening/closing member 41 depending on the change in thetemperature. The correction unit 74 is configured to compensate for theerror that results from changes in the exterior temperature. Thecorrection unit 74 corrects the detected movement amount using, forexample, the formula shown below.

l _(c) =l _(t)×{1+α(t−t ₀)}

In the formula, l_(c) is the corrected movement amount, l_(t) is theactual measured value of the movement amount, α is the coefficient oflinear thermal expansion of the wire 51, t is the exterior temperatureat the time when the movement amount is detected, and t0 is the exteriortemperature when setting the zero-point.

Since the error resulting from expansion and contraction of the wire 51is corrected in this way, the ventilation quantity can be calculatedmore accurately.

Although in this embodiment the correction is performed using theexterior temperature as the ambient temperature of the wire 51, it isalso acceptable to detect the temperature near the wire 51 and use thedetected temperature for the correction.

In addition to logging the history of the ventilation quantity in thememory 71, the recording unit 75 displays the ventilation quantity on adisplay panel 76 (first output unit and second output unit) of thecontrol panel 72 (see FIG. 9). The recording unit 75 records the historyof the ventilation quantity, which comprises the ventilation quantitiesobtained by converting the opening degree of the ventilation passage 40and the dates (year/month/day) and times of day when the ventilationquantities were recorded, in the memory 71. The recording unit 75 logsthe ventilation quantity history at the following three timings. Thefirst timing is when the refrigerator unit for container 1 startsrunning. That is, the recording unit 75 logs the ventilation quantityand other data when the compressor 31, evaporator fan motor 37, andcondenser fan motor 35 are driven and the refrigerator unit forcontainer 1 starts cooling the interior IS of the container C. Thesecond timing is each time a specific amount of time elapses or at aspecific time of day. For example, the recording unit 75 might log theventilation quantity and other data once per day at a specific time(e.g., 00:00 AM). The third timing is when the opening degree of theventilation passage 40 is changed. That is, the recording unit 75 logsthe ventilation quantity and other data when the opening/closing member41 is moved and the opening degree of the ventilation passage 40 ischanged. By logging the ventilation quantity and other data at thesethree timings, the ventilation quantity can be logged in a more detailedfashion. Thus, the ventilation quantity can be known in more detail.Additionally, the value of the ventilation quantity is logged accordingto a prescribed incremental value. For example, in consideration of theconversion error between the opening degree and the ventilationquantity, the ventilation quantity might be logged in increments of 5m³/h.

The control panel 72 is arranged in the external storage space SP1 ofthe front face 21 and faces the exterior OS. As shown in FIG. 9, thecontrol panel 72 is provided with a display panel 76 and input keys 77.The display panel 76 displays such information as the interiortemperature of the container C and the ventilation quantity obtained byconverting the opening degree data. The input keys 77 are used to turnthe refrigerator unit for container 1 on and off and to enter operationdetails.

The ventilation quantity is not only displayed on the display panel 76but also outputted by the output unit 78 (first output unit and secondoutput unit). The output unit 78 outputs the logged history of theventilation quantity. The output unit 78 is, for example, a printerserving to print the ventilation quantities, dates (year/month/day), andtimes that have been logged, a write device configured to write theventilation quantities and other data to a recording medium aselectronic data, or an output port for transmitting the ventilationquantities and other data to another information terminal through acommunication cable or wireless connection as electronic data. Anexample of the ventilation quantity history list outputted by the outputunit 78 is shown in FIG. 10. In this history list, the ventilationquantity D1 is a ventilation quantity logged when the opening degree ofthe ventilation passage 40 is changed. The ventilation quantity D2 is aventilation quantity logged at a specific time of day. The ventilationquantity D3 is a ventilation quantity logged when the refrigerator unitfor container 1 started operating. The ventilation quantities D1, D2, D3are outputted together with the temperatures T1 and the date(year/month/day) and time T2 when the ventilation quantities D1, D2, D3,and the interior temperature T were detected. The temperatures T1 arethe temperature setting, the interior temperature of the container Cdetected during transport, etc. The temperatures T1 and the ventilationquantities D1, D2, D3 are detected and recorded at a plurality of timesT2 during transport.

Logging and Output of Ventilation Quantities

The procedure for logging the ventilation quantity will now be describedbased on the flowchart shown in FIG. 11.

In step S1, the ventilation passage 40 is closed or opened. In thisembodiment, the opening degree of the ventilation passage 40 is changedmanually by sliding the opening/closing member 41. When theopening/closing member 41 is moved, the wire 51 is either pulled orpushed in accordance with the movement of the opening/closing member 41.The movement of the wire 51 is transmitted to the wire winding drum 52and the wire winding drum 52 rotates.

In step S2, the opening degree is detected. In this embodiment, theposition meter 53 detects the rotational angle of the wire winding drum52. The opening degree of the ventilation passage 40 is outputted fromthe opening degree detecting device 50. That is, the opening degree ofthe ventilation passage 40 is outputted in the form of the rotationalangle of the wire winding drum 52. The outputted opening degree is sentto the control unit 70 of the controller 7.

In step S3, a conversion calculation is executed to obtain theventilation quantity. In this embodiment, the opening degree of theopening/closing member 41 is converted to a ventilation quantity usingeither the first conversion formula F1 or the second conversion formulaF2.

In step S4, the ventilation quantity and other data is logged anddisplayed. In this embodiment, the conversion-calculated ventilationquantity and the date (year/month/day) and time it was logged arerecorded in the memory 71 and the ventilation quantity is displayed onthe display panel 76. The logging and display of the ventilationquantity and other data are performed at the aforementioned threetimings. The output unit 78 outputs the history of the ventilationquantity and other data.

Characteristic Features

(1) With this refrigerator unit for container 1, the interior IS of thecontainer C is ventilated and the ventilation quantity is logged. As aresult, the fact that the opening/closing member 41 was moved andventilation was conducted during transport of a container C can beconfirmed afterwards by checking the ventilation quantity history.

In particular, it is difficult to check the history of the openingdegree of the opening/closing member 41 and the ventilation quantitywhen the opening/closing member 41 is moved a plurality of times.However, with this refrigerator unit for container 1, the history of theventilation quantity can be known easily by outputting the loggedventilation quantities.

For example, in the case of a container C used to transport fruit, it isnecessary to exhaust the ethylene gas generated by the fruit and draw infresh outside air. Therefore, it is important to manage the ventilationquantity in order to maintain the freshness of the fruit. With thisrefrigerator unit for container 1, by logging the ventilation quantity,a transport company transporting the container C can provide the fruitowner with a guarantee that a certain amount of ventilation isconducted.

(2) With this refrigerator unit for container 1, the opening degree ofthe ventilation passage 40 is detected based on the amount of movementof the opening/closing member 41 and the ventilation quantity iscalculated based on the opening degree. As a result, ventilationquantity can be obtained with a system having a simple configuration.

Other Embodiments

(1) In the embodiment described above, the ventilation quantity is foundusing the movement amount of the opening/closing member 41 and aconversion formula. It is also acceptable to find the ventilationquantity based on the speed of the ventilated air and the opening crosssectional area. For example, as shown in FIG. 12( a), an air speedsensor 63 (air speed detecting means) can be provided in the ventilationpassage 40. In such a refrigerator unit for container as this, an airspeed sensor 63 that detects the speed of the air passing through theexhaust passage 43 is provided in the exhaust passage 43. The controlunit 70 logs data (ventilation data) that includes the air speed datadetected by the air speed sensor 63 and the opening cross sectionalarea. The control unit 70 converts the air speed data into a ventilationquantity by finding the product of the detected air speed and theopening cross sectional area of the exhaust port 45 and logs theresulting ventilation quantity. In view of improving the detectionaccuracy, it is preferred that the air speed sensor 63 be mounted on theside where the opening/closing member 41 begins to open.

(2) Although in the embodiment described above, the ventilation quantityis found using the movement amount of the opening/closing member 41 anda conversion formula, when the refrigerator unit for container 1 isprovided with a blower device 47 for ventilation as shown in FIG. 12(b), it is also acceptable to detect the output of the blower device 47and log the detected output data (ventilation data). It is alsoacceptable to convert the output data into a ventilation quantity andlog the ventilation quantity. The blower device 47 conducts ventilationby creating a flow of air that flows from the second chamber R2 to theexterior OS and a flow of air that flows from the exterior OS to thefirst chamber R1. Since the ventilation quantity is affected by theoutput of the blower device 47, the controller 70 can find theventilation quantity based on the output of the blower device.

(3) In the embodiment described above, the ventilation quantity is foundusing the movement amount of the opening/closing member 41 and aconversion formula. It is also acceptable to find the ventilationquantity by detecting the pressure difference between the exterior OSand the interior IS. For example, as shown in FIG. 12( c), there may bea refrigerator unit for container 1 provided with an exterior pressuresensor 64 (pressure detecting means) that detects the pressure of theexterior OS and an interior pressure sensor 65 (pressure detectingmeans) that detects the pressure of the first chamber R1 or the secondchamber R2. In such a refrigerator unit for container 1 as this,pressure difference data (ventilation data) indicating the differencebetween the exterior pressure detected by the exterior pressure sensor64 and the interior pressure detected by the interior pressure sensor 65are logged. The output data can then be converted into a ventilationquantity and logged.

The ventilation of the air in the interior IS of the container C takesplace due to the pressure difference between the exterior OS and theinterior IS. In other words, the existence of a pressure differencebetween the exterior OS and the interior IS causes a flow of air thatflows from the exterior OS to the interior IS or a flow of air thatflows from the interior IS to the exterior OS to be generated. As aresult, ventilation occurs. Thus, the ventilation quantity can be foundby detecting the pressure difference between the exterior OS and theinterior IS.

It is also acceptable to log freight quantity data related to thequantity of freight in the interior IS of the container C and find theventilation quantity using the freight quantity data. The quantity offreight in the interior IS of the container C affects the pressuredifference between the exterior OS and the interior IS. In other words,the pressure inside the container C is different when the quantity offreight in the interior IS of the container C is large than when thequantity of freight is small. Thus, the ventilation quantity can befound by taking the freight quantity data into consideration.

(4) Although in the embodiment described above, the opening degree ofthe ventilation passage 40 is detected by using a wire 51 to transmitthe movement of the opening/closing member 41 to an opening degreedetecting device 50, it is also acceptable to detect the opening degreeof the ventilation passage 40 with a photoelectric sensor 66 (openingdegree detecting means) as shown in FIG. 13( a). The photoelectricsensor 66 is arranged to face the opening/closing member 41 in thedirection in which the opening/closing member 41 moves so that it candetect the distance between itself and the opening/closing member 41.With this arrangement, the movement amount of the opening/closing member41 and thus the opening degree of the ventilation passage 40 imposed bythe opening/closing member 41 can be detected. It is also acceptable todetect the amount of movement of the opening/closing member 41 usingradio waves instead of light.

(5) Although in the embodiment described above, the opening degree ofthe ventilation passage 40 is detected by using a wire 51 to transmitthe movement of the opening/closing member 41 to an opening degreedetecting device 50, it is also acceptable to detect the opening degreeof the ventilation passage 40 with a plurality of reed switches 67(opening degree detecting means) as shown in FIG. 13( b). The reedswitches 67 are arranged parallel to the slide direction of theopening/closing member 41 and are configured to enter an on state whenexposed to a magnetic force. A magnet 68 is provided on theopening/closing member 41 and the magnet 68 moves over the reed switches67 when the opening/closing member 41 moves. Thus, the movement amountand position of the opening/closing member 41 can be detected based onthe on/off status of the reed switches 67.

It is also acceptable to detect the opening degree of the ventilationpassage 40 using a plurality of limit switches. In such a case, thelimit switches are arranged parallel to the slide direction of theopening/closing member 41 and are configured to enter an on state whensubjected to mechanical contact. A lever configured and arranged tocontact the limit switches is provided on the opening/closing member 41so that when the opening/closing member 41 moves, the limit switches inpositions through which the opening/closing member 41 has passed areturned on. Thus, the movement amount of the opening/closing member 41can be detected based on the on/off status of the limit switches.

(6) Although in the embodiment described above, the movement of theopening/closing member 41 is transmitted to the opening detecting device50 by means of a wire 51, it is also acceptable to transmit the movementof the opening/closing member 41 to the opening degree detecting device50 with a gear 55 (transmitting means) as shown in FIG. 13( c). The gear55 has a circular shape and is arranged to the side of theopening/closing member 41. A linear gear 56 is provided on a side edgeof the opening/closing member 41 and the linear gear 56 of theopening/closing member 41 meshes with the gear 55. A position meter 53is mounted to the rotational center of the gear 55 and serves to detectthe rotational angle of the gear 55. Thus, when the opening/closingmember 41 moves up and down, the gear 55 rotates (see solid arrow A6)and the position meter 53 detects the movement amount of theopening/closing member 41 in the form of the rotational angle of thegear 55. As a result, the opening degree of the ventilation passage 40can be detected.

(7) Although in the embodiment described above, the ventilation passage40 is opened and closed by sliding the opening/closing member 41linearly up and down, it is also acceptable to open and close theventilation passage 40 by rotating an opening/closing member 48 as shownin FIG. 14( a). The opening/closing member 48 has a circular shape andis mounted to the upper portion of the front face 21 such that itscenter is positioned between the intake port 44 and the exhaust port 45.Two openings 481, 482 corresponding to the intake port 44 and theexhaust port 45 are provided in the opening/closing member 48. When theopening/closing member 48 rotates (see the solid arrow A7), the twoopenings 481, 482 overlap the intake port 44 and exhaust port 45 andthereby open the intake port 44 and exhaust port 45. When the portionsof the opening/closing member 48 other than the openings 481, 482overlap the intake port 44 and exhaust port 45, the intake port 44 andexhaust port 45 are closed. In FIG. 14( a), the two openings 481, 482are positioned such that the ports are completely closed. When anopening/closing member 48 like that shown in FIG. 14( a) is rotated 90degrees from a position where the portions of the opening/closing member48 other than the openings 481, 482 are aligned with the intake port 44and exhaust port 45, the ventilation passage 40 is completely closed.When the opening/closing member 48 is rotated 90 degrees further or 90degrees in the opposite direction to a position where the two openings481, 482 are aligned with the intake port 44 and exhaust port 45, theventilation passage 40 is completely open. A position meter 53 ismounted to the center of the gear 48 and serves to detect the rotationalangle of the opening/closing member 48 as the movement amount of theopening/closing member 48, i.e., as the opening degree of theventilation passage 40.

It is also acceptable to provide the position meter 53 in a positionseparated from the position meter 53 instead of at the center of theopening/closing member 48. For example, as shown in FIG. 14( b), anopening degree detecting device 50 comprising a wire winding drum 52 anda position meter 53 arranged at the center of the wire winding drum 52can be arranged in a position separated from the opening/closing member48 and a wire 51 can be used to transmit the rotation of theopening/closing member 48 to the wire winding drum 52. It is alsoacceptable to provide a circular gear 57, 58 (transmitting means) at thecenter of each of the opening/closing member 48 and the position meter53 and to provide another circular gear 59 (transmitting means) that ispositioned between and meshes with the gears 57, 58, as shown in FIG.14( c). With this arrangement, too, the rotation of the opening/closingmember 48 is transmitted to the position meter 53 by the gears 55, 57,58, 59 and the opening degree of the ventilation passage 40 can bedetected. When a wire winding drum 52 or gears 57, 58, 59 are used asdescribed above, the resolution with which the movement amount of theopening/closing member 48 is detected can be changed easily by changingthe diameter of the wire winding drum 52 or the gear ratio of the gears57, 58, 59.

(8) In the embodiment described above, the intake port 44 and theexhaust port 45 are provided closely adjacent to the first chamber R1and the second chamber R2, respectively. However, due to variouscircumstances, there are cases in which the intake port 44 and theexhaust port 45 are provided in positions separated from the firstchamber R1 or second chamber R2. In such cases, a duct joining theintake port 44 and first chamber R1 and a duct joining the exhaust port45 and second chamber R2 can be provided. For example, consider a casein which the exhaust port 45 and intake port 44 are provided in thelower portion of the front face 21 such that the intake port 44 isseparated from the first chamber R1, as shown in FIG. 15. In such a caseas this, it is acceptable to provide a duct 49 that runs from the firstchamber R1, passes through the second chamber R2, penetrates thethermally insulated wall 26 and the front face 21, and connects to theintake port 44. In this way, even though the intake port 44 is in aposition separated from the first chamber R1, air drawn into the intakeport 44 from the exterior OS can be delivered to the first chamber R1 bythe duct 49 (see solid arrow A6).

In the case of marine freight containers C, there are times when therefrigerator unit for container runs at terminals and the like in orderto keep the freight cool after disembarkation. In such cases, agenerator G is often installed on the upper portion of the front face 21as shown in FIG. 15 because a power supply is not available.Consequently, the intake port 44 and exhaust port 45 cannot be providedin the upper portion of the front face 21 and must be provided in thelower portion of the front face 21. Therefore, particularly in caseswhere ventilation is accomplished by utilizing pressure differences, itis effective to provide a duct(s) 49 as just described in order toventilate the container.

(9) Although in the embodiment described above, ventilation quantitiescalculated based on the opening degree data are outputted to the displaypanel 76 of the control panel 72 and the output unit 78, it is alsoacceptable to output such ventilation data as opening degree data.

(10) Although in the embodiments described above, such data as openingdegree data, air speed data, output data, pressure difference data, andfreight quantity data that indicate the ventilation quantity indirectlyare detected and logged, it is also acceptable to provide a ventilationquantity sensor that detects the ventilation quantity directly and logthe detected ventilation quantity.

(11) Although in the embodiments described above, the ventilationquantity is logged in a controller 7 arranged in the exterior storagespace SP1, it is also acceptable to log the ventilation quantity in anexternal computer terminal, such as a desktop computer or notebookcomputer.

By using a refrigerator unit for container in accordance with thepresent invention, the quantity of air ventilated in the interior of acontainer can be known because recorded ventilation data related to thequantity of ventilated air can be reviewed afterwards.

1. A refrigerator unit for container, comprising: a ventilation unitconfigured to ventilate air from an interior of a container; anacquisition unit configured to acquire ventilation data related to aquantity of air ventilated by the ventilation unit; and a recording unitconfigured to record the ventilation data acquired by the acquisitionunit, the recording unit being configured to record the ventilation datawhen the refrigerator unit starts running.
 2. A refrigerator unit forcontainer, comprising: a ventilation unit configured to ventilate airfrom an interior of a container; an acquisition unit configured toacquire ventilation data related to a quantity of air ventilated by theventilation unit; and a recording unit configured to record theventilation data acquired by the acquisition unit, the recording unitbeing configured to record the ventilation data each time a specificamount of time elapses or at a specific time of day.
 3. A refrigeratorunit for container, comprising: a ventilation unit configured toventilate air from an interior of a container; an acquisition unitconfigured to acquire ventilation data related to a quantity of airventilated by the ventilation unit, the acquisition unit being furtherconfigured to acquire data that indirectly indicates the quantity of theair ventilated by the ventilation unit as at least part of theventilation data; a recording unit configured to record the ventilationdata acquired by the acquisition unit; and a conversion unit configuredto convert the ventilation data into a quantity of air.
 4. Therefrigerator unit in accordance with claim 3, wherein the conversionunit has a plurality of different converting devices configured fordifferent ventilation unit configurations.